I am trying to send a email to one of my client , getting following error The following recipient(s) could not be reached: > > 'M.Prakash@xxxxxxxx' on 10/23/2004 1:52 PM > There was a SMTP communication problem with the recipient's email server. Please contact your system administrator. > <egs-exh.server.local #5.5.0 smtp;554 Service unavailable; > [217.165.51.61] blocked using dul.dnsbl.sorbs.net, reason: Dynamic IP > Address See: http://www.dnsbl.sorbs.net/lookup.shtml?217.165.51.61> But if I try to send the mail from other domain the mail reaches to the above email address. Can anyone highlight on this and what is the remedy for this